- a free tool to help users check their browsers for plugins which might be old or insecure, exposing the user to risk.
Mozilla PluginCheck - another free alternative, and though it is sponsored by Mozilla, who brings us Firefox, it works in most any browser.
Securing Your Browser (US-CERT) - helps users understand concepts like "trusted sites" and how they impact security.
NoScript- a Firefox plugin which allows users to visit web sites with scripting disabled by default. Not for the faint of heart, but can dramatically reduce the risk of a browser-based compromise.